Corrupt BLOB field after restore of online backup

Hi, we are using DB2 9.7 fix pack 3 on an AIX server. I recently restored an online backup and redirected into an new DB name. We noticed that in one record in a table that contains a BLOB column, the BLOB column was padded with over 40,000 NULL's. The same record in the original table is fine, it contains a PDF image. How is this possible? Could it be a backup or restore or roll forward issue? Also, does anyone know how I can query the table to find other records that contain multiple NULLs in the BLOB column?